Mucosal Advancement Flap for High Fistula in Ano – Our Experience

A BSTRACT Background: High cryptoglandular fistulas present a therapeutic challenge, balancing eradication and continence preservation. Aim: To evaluate the efficacy, safety, and functional outcomes of the mucosal advancement flap (MAF) technique for high anal fistula in a high volume colorectal unit. Methods: A retrospective review was conducted of consecutive patients undergoing MAF for high cryptoglandular anal fistula between January 2021 and July 2024. Patients with inflammatory bowel disease, trauma, malignancy, or radiation induced fistulas were excluded. Clinical healing was defined as complete closure of both openings without discharge or induration at ≥3 months. Recurrence was defined as a new abscess or persistent external opening after documented healing. Results: Among 151 operations for complex fistula performed during the study period, 25 patients (13 males, 12 females; mean age 40 years) underwent MAF. Twenty cases (80%) were transsphincteric, and 19 (76%) had posterior internal openings. Two patients (8%) developed complications, urinary retention ( n = 2) and abscess recurrence ( n = 1) requiring re intervention (fistulotomy). Primary healing was achieved in 23 of 25 patients, yielding a healing rate of 92.0% (95% CI 74–99%). No patient reported new onset fecal incontinence. The mean follow up was 16 months; 18 (72%) completed at least 1 year follow up. Conclusions: MAF is a safe and effective sphincter sparing technique for high cryptoglandular fistulas, achieving high healing rates and preserving continence. Larger prospective studies with validated continence assessment are warranted.